No. DE-A-25 14 941 discloses a roller screen comprising a screen assembly which has a protective enclosure of self-supporting construction and which is clasped by two pairs of holding jaws. Articulated arms are pivotally mounted on the opposite ends of the enclosure and on two wall brackets respectively spaced from the opposite ends of the enclosure. A shaft carrying a screen in the form of an awning canopy is mounted in hinge members which are attached to the two wall brackets to support the weight of the canopy when the canopy is rolled onto the shaft. The end regions of the enclosure (outside the two wall brackets) are therefore subject to flexure. The enclosure is therefore provided with a stiffening profile and, particularly in the case of very wide awnings, must have relatively thick walls. The assembly is therefore quite heavy and difficult to handle during mounting.
This deficiency is to some extent reduced in the screen assembly of the roller screen disclosed in No. GB-A No. 834 097 because here the intention is to accommodate the screen assembly in depressions in a supporting wall, the screen assembly being supported over its entire length by the lower edge of such a wall depression. However, by virtue of this form of mounting, the range of applicability of this assembly is distinctly curtailed.
In general, however, in the mounting of screen assemblies of roller screens such as that disclosed in No. DE-A No. 29 16 496, the mounting means include brackets which are fastened to a supporting surface such as a wall or ceiling. The screen assembly, which is produced as a mounting unit, is then mounted on or attached to the brackets. A longitudinally extending supporting element, such as a mounting tube, is often provided and this is connected to the brackets.
Screen assemblies such as awning assemblies in co-operating wide awning canopies are quite heavy, particularly when the awning assembly is provided with articulated awning arms which, in the retracted condition, are accommodated within a protective enclosure forming part of the awning assembly. These awning arms must be strong enough to support the awning in strong, gusting wind and add considerably to the weight of the awning assembly. Due to the high weight, two fitters are usually required for mounting the awning assembly on a support surface.
Awning assemblies of roller awnings are usually provided with a mounting tube which, when the roller awning is mounted on a support surface, is disposed on the underside of the awning assembly. Therefore, when it is necessary to lift an awning assembly which is lying on the ground with the mounting tube underneath, and to mount the awning assembly in an overhead position, the awning assembly must be grasped from above. It is therefore normal for the fitters to grasp the mounting tube and the top bar which is attached to the outer end of the awning canopy. However, this causes difficulty when the awning assembly has to be lifted above head height because, in this process, the hand grip must be changed. In addition, the drop bar (which is normally relatively thin) can be bent. In many cases, the awning assembly is therefore placed on the ground with the mounting tube uppermost, instead of in its normal lower position, so that the awning assembly may be more easily gripped and lifted by the mounting tube. Unfortunately, when lifting an awning assembly in this way, there is a tendency for the fitters to tilt or roll the awning assembly as it is lifted from the ground and so the rolled canopy, which is then nearest to the ground, can be soiled or even damaged.
These problems naturally do not occur with light weight awning assemblies. If the canopy is rolled onto a spring roller in the same way as a window blind and extends only over the width of a narrow window, as in the roller awning disclosed in U.S. Pat. No. 1,788,173, a single fitter can lift the entire awning assembly in both hands and mount it in an overhead position without any trouble.